Well, looking back at some of those posts, the main difference in European vs. US versions has to do with firmware configuration. The European versions are programmed to default to PAL and the US versions are programmed to look for NTSC first. I can't imagine that that's the problem.
Still, there has to be something that's affecting whether or not the unit is gapless.
Seriously, I'd like to try out a DVD-A that someone else found to be gapless on a HD841 and see how it plays on mine. Anyone willing to loan me one? Anyone willing to try the DVD-A that I burned and see if it's gapless on their HD841? It may be that I'm not burning good DVD-A's. Whatever it is, I'd like to figure it out.